<?php
/*
 *   命名规则   前缀加   f_date_ 
 * 
 */



function check_date($date) { //检查日期是否合法日期
	$dateArr = explode("-", $date);
	if (is_numeric($dateArr[0]) && is_numeric($dateArr[1]) && is_numeric($dateArr[2]))
	{
		return checkdate($dateArr[1],$dateArr[2],$dateArr[0]);
	}
	return false;
}

function check_time($time) { //检查时间是否合法时间
	$timeArr = explode(":", $time);
	if (is_numeric($timeArr[0]) && is_numeric($timeArr[1]) && is_numeric($timeArr[2])) {
		if (($timeArr[0] >= 0 && $timeArr[0] <= 23) && ($timeArr[1] >= 0 && $timeArr[1] <= 59) && ($timeArr[2] >= 0 && $timeArr[2] <= 59))
			return true;
		else return false;
	}
	return false;
}

function DateDiff($date1, $date2, $unit = "") { //时间比较函数，返回两个日期相差几秒、几分钟、几小时或几天
	switch ($unit) {
		case 's': $dividend = 1; break;
		case 'i': $dividend = 60; break;
		case 'h': $dividend = 3600; break;
		case 'd': $dividend = 86400; break;
		default: $dividend = 86400;
	}
	$time1 = strtotime($date1);
	$time2 = strtotime($date2);
	if ($time1 && $time2)
		return (float)($time1 - $time2) / $dividend;
	return false;
}